This invention relates to a hollow golf club shaft formed of a fiber-reinforced plastic (FRP).
Golf club shafts formed of FRP are now increasingly used for both iron and wood clubs. For the production of FRP shafts, the filament winding method and the sheet winding method are generally used. In the former method, a fiber tow impregnated with a matrix resin is wound around a mandrel. In the latter method, a prepreg sheet composed of uniaxially oriented fibers impregnated with a matrix resin is wound around a mandrel. The filament winding method has a merit that it is possible to continuously or intermittently change the winding angle relative to the centerline axis of the shaft so as to control the kick point and flexural rigidity of the shaft. Since, however, the winding angle cannot be abruptly changed, it is impossible to impart great changes in flexural rigidity along the length of the shaft by the filament winding method.